Dairies and feedlots house cattle in barns. The barns contain stalls for the cattle. The cattle are directed from their stalls to the feeding areas. In a dairy barn, milking cows are directed into a milking parlor.
The trend in cattle operations has been to increase the density of animals per acre of land. This increases the yield on fixed assets. Thus, today cattle operations have high cattle densities. With high densities, the problem of manure disposal arises. Cattle operations with low cattle densities simply allow the manure to naturally degrade. Cattle operations with high cattle densities do not have this luxury and must remove the manure from the cattle areas.
The stalls in cattle barns use bedding material to soften the ground and make the cattle more comfortable. In addition, the bedding material absorbs and mixes with the cattle waste. To clean the stall, the soiled bedding material is removed and replaced with clean bedding material.
Hay has traditionally been used as bedding material. Some other bedding materials include sawdust and mats. However, problems arise with these bedding materials in that they house pathogens which can lead to illness or infections in cows.
Sand is replacing hay and other bedding materials in many barns. Sand is comfortable for the cattle to bed in. Sand is cool in the summer and, when of the proper particle size, is less abrasive on the cows. Sand also drains well. Consequently, sand is drier and resists bacteria growth. Thus, sand is cleaner than traditional bedding material.
Dairy cattle in particular require sanitary bedding in order to minimize the occurrences of mastitis. Mastitis is an inflammation of the mammary gland caused by bacterial pathogens or injury. Mastitis reduces milk yields and alters the composition of milk. In many cases, mastitis causes permanent injury to the animal. In all cases, mastitis causes economic losses for the dairyman.
Unfortunately, soiled sand is harder to dispose of that soiled hay. While soiled hay can be composted, soiled sand cannot. The very characteristic that makes sand desirable as a bedding material, drainage, makes it difficult to compost, as composting the waste requires moisture.
In the prior art, the soiled sand is removed from the barn and disposed of or processed. When disposed of, it must be disposed of in compliance with environmental regulations. Some dairies buy land solely for sand disposal purposes and truck the soiled sand to the designated land for dumping. Soiled sand disposal adds to the cost of cattle operations and decreased the yield on fixed assets.
The soiled sand can also be processed. U.S. Pat. No. 5,950,839 separates the sand by agitating an aqueous sand slurry with paddles to draw off the finer organic components, and then conveys the sand and coarser organic components up an incline with a screw conveyor. The material is sprayed to separate the sand from the coarser organic components. The equipment required to process the sand is expensive and believed to require frequent maintenance.